Cr-doped GaAs/AlGaAs semi-insulating multiple quantum well photorefractive devices

Semi-insulating multiple quantum well photorefractive devices using GaAs/Al0.29Ga0.71As with an electric field applied perpendicular to the layers are demonstrated. Semi-insulating behavior is obtained by doping with Cr(1016/cm3) during epitaxial growth of the material. Diffraction efficiencies as high as 3% with an applied voltage of 20 V and microsecond response times are obtained in a 2 μm thick device. These devices are of importance for implementation of fast and sensitive two-dimensional optical information processing systems at wavelengths compatible with current diode lasers without the spatial-bandwidth limitations of thick photorefractive materials.